Method and apparatus for cleaning fabrics, floor coverings, and bare floor surfaces utilizing a soil transfer cleaning medium

ABSTRACT

An apparatus and method for cleaning fabrics, floor coverings, and bare floor surfaces utilizing a soil transfer cleaning medium is disclosed. A method of mechanically removing soil from a surface intended to be cleaned includes the steps of successively and repeatedly: wetting a portion of a cleaning medium with a cleaning liquid; extracting any soil and at least some of the cleaning liquid from the previously wetted portion of the cleaning medium; and wiping the surface intended to be cleaned with the portion of the cleaning medium so as to transfer soil from the surface intended to be cleaned to the cleaning medium. Portable and vehicle-based devices may be utilized to practice the method of cleaning.

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application is a continuation-in-part of U.S. Ser. No.10/081,374, now U.S. Pat. No. ______, which claimed the benefit ofpriority of U.S. Provisional Patent Application Ser. No. 60/299,561filed June 20, 2001.

[0002] This application is related to U.S. Ser. No. 10/371,940, whichalso claimed the benefit of priority of U.S. Provisional PatentApplication Ser. No. 60/299,561 filed June 20, 2001, wherein all ofthese related applications are incorporated by reference herein.

FIELD OF THE INVENTION

[0003] The present invention relates generally to surface maintenance orconditioning machines, and more particularly to those machines employingone or more surface maintenance or conditioning appliances or tools toperform a surface cleaning task.

BACKGROUND OF THE INVENTION

[0004] In general, proper carpet maintenance involves regular vacuumingand periodic cleaning to remove soil by methods such as hot waterextraction, shampooing, bonnet cleaning, foam cleaning, etc. Some of thesoil is loosely found between carpet fibers while other soil is heldupon the carpet fibers by some means such as electrostatic forces, vander Waals forces, or oil bonding. Still other soil is mechanicallytrapped by carpet fibers. Regular vacuuming is essential as it removessome of the loose soil that damages the fibers. Vacuuming maintains thesurface appearance of a carpet and keeps the level of soil in the pileat an acceptable level. Vacuuming removes only particulate soil and someunbound or loosely bound surface dirt; therefore, other methods ofcleaning are periodically required to improve the appearance of thecarpet. Wet cleaning methods are better for removing oils, greases,bound dirt, and other forms of matter that cause soiling on carpet.These methods are often used by professional cleaners and trainedpersonnel.

[0005] One type of surface maintenance machine for carpet cleaning isreferred to as a bonnet cleaner. Bonnet cleaners employ an absorbentbonnet or pad (hereinafter referred to as the “pad”) attached to arotary driver for rotating the pad about an axis generally perpendicularto the carpet surface. Cleaning liquid is sprayed directly onto thecarpet followed by the rotating pad used to agitate the carpet andtransfer soil from the carpet onto the bonnet, i.e., the pad. Since thepad is commonly two-sided, the pad may be reversed once one side of thepad gets soiled to a selected level. The pad may be periodicallyreplaced and later cleaned depending upon the application and wearcharacteristics of the pad.

[0006] The soil transfer process of the bonnet cleaners may becharacterized as a “circular engagement process” since the pad rotatesrelative to the carpet surface. The method employed by bonnet cleanersdoes have the advantage of being fast drying if a relatively smallamount of cleaning liquid is employed. However, limitations of bonnetcleaners include transferring soil from soiled areas to a relativelycleaner area, leaving much of the cleaning fluid in the carpet, andhaving the potential to damage the carpet. With respect to the latter,some carpets, particular twisted ply variations, may be damaged byaggressive engagement with the rotating pad. Additionally, the bonnetcleaning process is a relatively labor intensive process since the padrequires frequent soil monitoring and frequent removal of soiled pads.

[0007] Yet another limitation of bonnet cleaners is the relativelyuncontrolled use of cleaning liquid in the carpet cleaning process assome areas of the carpet may receive more cleaning liquid spray thanother areas. Reliance on operator spraying of cleaning liquid to thecarpet surface may result in overwetting of some areas and underwettingof other areas.

[0008] Another type of surface maintenance machine intended for carpetcleaning is referred to as an “extractor machine.” Extractor machinesare commonly used for deep carpet cleaning. In general, an extractor isa transportable self-contained device which (i) sprays cleaning liquiddirectly onto the carpet to create a wetted carpet portion, (ii)agitates the wetted portion with a brush, and (iii) removes some of thecleaning liquid and soil in the carpet through a vacuum system.Generally, in the extraction process a relatively large quantity ofcleaning liquid is applied on the carpet. While the vacuum systemrecovers a portion of the applied cleaning liquid, a significant portionis retained by the carpet. As a consequence, carpet drying times aresubstantially longer than in the bonnet cleaning process. Excessivecarpet wetting may promote the growth of fungus and/or bacteria withinthe carpet. Additionally, carpet overwetting may also cause surfacestains to appear or reappear as underlying soil or stains migrate fromthe bottom of the carpet to its surface. Additionally, extractors aregenerally limited to a single operational direction as the steps ofwetting, agitation, and vacuuming are sequentially performed. As aresult, extractor machines may be difficult to maneuver in someenvironments, i.e., complex floor layouts.

SUMMARY AND OBJECTS OF THE INVENTION

[0009] An object of the present invention is the provision of a carpetcleaning machine promoting efficient use of cleaning liquid in carpetcleaning.

[0010] Another object of the present invention is to enhance cleaningarea per unit of cleaning solution.

[0011] Another object of the present invention is to provide a cleaningmethod that permits a carpet to dry more rapidly.

[0012] Yet another object of the present invention is to provide acarpet cleaning process that has the ability to lift carpet pile whichexposes more of the carpet fibers to the surrounding drying air so as topermit the carpet to dry more rapidly than if the pile was not lifted.

[0013] Yet another object of the present invention is the provision of acleaning process and apparatus for cleaning a variety of surfaces,including but not limited to floor surfaces, stairways, walls, andupholstered furniture or other fabric surfaces.

[0014] The present invention is directed both to a method of cleaningsurfaces and an apparatus for performing the method. In a broad sense,the cleaning process is similar to a damp cloth wiping operation whereinsoil from a surface is transferred to the damp cloth. More particularly,the cleaning process utilizes:

[0015] In accordance with the present invention, a revolving cleaningmedium, which after being wiped against a surface intended to be cleanedis wetted, followed immediately by the step of extracting so as toremove cleaning solution and any soil from the cleaning medium, andagain wiped against the surface—the process revolving or repeating. In apreferred operation, one portion of the cleaning medium is wetted withcleaning liquid, while another portion is being extracted to remove soiland cleaning liquid therefrom, and while yet another portion is beingwiped against the surface to transfer soil from the surface to thecleaning medium. The process continues in a revolving or cyclical mannerso that each portion of the cleaning medium is sequentially wetted,extracted, and wiped against the surface.

[0016] The method of cleaning surfaces in accordance with the presentinvention includes the steps of (i) wetting a revolving cleaning mediumwith a cleaning solution, (ii) followed by removing at least some of thecleaning liquid from the revolving cleaning medium directly afterwetting by way of a moisture extraction device, and (iii) wiping thesurface with the revolving cleaning medium so as to transfer soil fromthe surface to the revolving cleaning medium and subsequently removingtransferred soil from the revolving cleaning medium.

[0017] In accordance with present invention, a transportable device isutilized to perform the cleaning process on a carpeted surface. Thedevice may be a relatively portable machine having a cleaning liquidtank, a soiled solution recovery tank, a vacuum system, and cleaninghead. The cleaning head may include a revolving cleaning medium andassociated drive mechanism. A vacuum extractor may be used to engage thecleaning medium to remove soil and at least some of the cleaning liquidfrom the cleaning medium.

[0018] In accordance with one embodiment of the invention the revolvingcleaning medium is configured as a pair of counter rotating cylindricalcleaning media having portions of each successively wetted, extracted,and wiped against a surface intended to be cleaned, with the processrepeating or revolving.

BRIEF DESCRIPTION OF THE DRAWINGS

[0019]FIG. 1 is a perspective illustration of one embodiment of acleaning machine according to the present invention.

[0020]FIG. 2 is a perspective view of a cleaning head of the cleaningmachine of FIG. 1.

[0021]FIG. 3 is another perspective view of the cleaning head of FIG. 1.

[0022]FIG. 4 is a side elevation view of the cleaning head of FIG. 1.

[0023]FIG. 5 is a cross sectional view of the cleaning head of FIG. 2,taken along lines 5-5.

[0024]FIG. 6 is a detailed side elevational view of a portion of thecleaning head of FIG. 5.

[0025]FIG. 7 is bottom plan view of the cleaning head of FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

[0026] The present invention is directed both to a method of cleaningsurfaces and an apparatus for performing the method. In a broad sense aswill subsequently be described, the cleaning process in accordance withthe present invention is similar to a damp cloth wiping operationwherein soil from a surface is transferred to the damp cloth.

[0027] More particularly, the cleaning process in accordance with thepresent invention utilizes a revolving cleaning medium which after beingwiped against a surface intended to be cleaned is wetted, followedimmediately by the step of extracting so as to remove cleaning liquid,in part, and any soil from the cleaning medium, and again wiped againstthe surface—the process revolving or repeating.

[0028] In a preferred operation, one portion of the cleaning medium iswetted with cleaning liquid, while another portion is being extracted toremove soil and cleaning liquid therefrom, and while yet another portionis being wiped against the surface to transfer soil from the surface tothe cleaning medium. The process continues in a revolving or cyclicalmanner so that each portion of the cleaning medium is sequentiallywetted, extracted, and wiped against the surface.

[0029]FIG. 1 illustrates an embodiment of a transportable floor surfacecleaning machine 10 according to the present invention. Moreparticularly, machine 10, for illustrative purposes, is illustrated asan AC powered (with power cord not shown) self-contained portable carpetextractor similar to those known in the art, including a cleaningsolution tank 12 for containing a cleaning liquid 13, such as a mixtureof water and a cleaning chemical, a recovery tank 14, a cleaning head20, a cleaning liquid dispenser 22, and a soiled solution extractionsystem 24 as further described herein. In operation, machine 10 issupported upon the ground surface 25 by rear wheels 26 and caster wheel28. Representative examples of self-contained portable carpet extractorshaving cleaning solution tank 12, recovery tank 14, cleaning liquiddispenser 22, and soiled solution vacuum extraction system 24 includemodels 1230 and 1260 extractors manufactured by Tennant Company,Minneapolis, Minn. In an illustrated embodiment, cleaning head 20 inaccordance with the present invention may be used in conjunction withone of such known walk-behind extractor machines and the like.

[0030] Cleaning head 20, in accordance with the present invention,includes a cleaning medium 40 and associated drive assembly 60 as ismore particularly shown in detail in FIGS. 2 and 3. Drive assembly 60selectively revolves cleaning medium 40 relative to cleaning head 20 andsurface 25. In operation, cleaning medium 40 is intended to be firstwetted with cleaning liquid 13 by cleaning liquid dispenser 22 andimmediately followed by a moisture extraction process before being wipedagainst surface 25 so as to transfer soil from surface 25 to cleaningmedium 40. In the extraction process, soil, as well cleaning solutionresulting from the step of wetting the cleaning medium just performed,is removed from cleaning medium 40 by soiled solution extraction system24. As further explained herein, cleaning medium 40 revolves duringoperation so that different portions of the cleaning medium 40 aresimultaneously being wetted with cleaning liquid 13, extracted byextraction system 24, or wiped against the surface 25.

[0031] Referring to FIGS. 1 through 3, cleaning head 20 is attached at aforward portion of the machine 10 via a coupling structure 48. Couplingstructure 48 includes a pair of fasteners 50 engaging apertures 52 incleaning head 20 and permitting cleaning head 20 to pivot or rotateabout an axis (not shown) passing through apertures 52. Cleaning head 20may include one or more assemblies which are movably connected togetherso that the assemblies may move relative to each other so as tofacilitate operational contact of the cleaning head 20 across undulatingfloor surfaces. In the illustrated embodiment, cleaning head includesforward and rear assemblies 54, 56, respectively. Forward assembly 54includes cleaning medium 40 in the form of a pair of counter rotatingcylindrical cleaning pads and/or brushes 62 and 64, and vacuum extractor42. Rear assembly 56 includes cleaning medium drive assembly 60,coupling structure 48, and caster wheel 28. Caster wheel 28 is coupledto cleaning head 20 to support at least a portion of machine 10 onsurface 25.

[0032] As described above, cleaning medium 40 functions to transfer soilfrom surface 25 to the cleaning medium 40. For a carpet surface,cleaning medium 40 functions to wipe the carpet and transfer soil fromcarpet fibers to the cleaning medium 40. A variety of differentmaterials may be utilized as a cleaning medium, including but notlimited to fabrics and absorbent foams, i.e., being “foam rubber” like.Cleaning medium 40 in one embodiment of the invention as illustrated inthe Figures includes a pair of cylindrical devices, i.e., cylindricalcleaning pads and/or brushes 62 and 64, hereafter referred to as simplybrushes. However, it should be noted herein that cylindrical brushes 62and 64, i.e. the cleaning medium 40, may be a constructed from anycombination of pad-like or bristle-like or foam-like materials, and thelike, which serve to transfer soil from the surface intended to becleaned unto the cleaning medium.

[0033] An exemplary construction of brushes 62 and 64 includes asubstrate, such as a woven synthetic fabric, having pile fibers tuftedthereinto. In one embodiment of the invention, the substrate has anappearance and feel that is similar to the surface fabric used on acommon paint roller. In some instances, it may be desirable tointersperse stiffer fibers, i.e., brush like bristles, into thesubstrate to enhance the agitation action of cleaning medium 40. A 0.75inch pile 100% nylon roller fabric may be utilized to cover an extrudedPVC tubing to form brush 62, 64. Other materials and tube forms may beutilized to form brush 62, 64.

[0034] With particular reference to FIGS. 4 through 7, brushes 62, 64 ofcleaning medium 40 are rotatably driven by cleaning medium driveassembly 60. Drive assembly 60 includes drive belts 70, 72, 74, 76 andelectric motors 80, 82, 84. Drive belt 70 is coupled to a commonrotating jackshaft 86 which is driven by three small electric motors 80,82, 84. Each motor 80, 82, 84 has an associated drive belt 72, 74, 76 tothe jackshaft 86. In alternative embodiments, a single electric motormay be utilized to rotatably drive cylindrical brushes 62 and 64. Asdepicted in FIGS. 5 and 6, cleaning medium brushes 62, 64 are rotated inopposite directions during operation. To facilitate cleaning head 20contact with floor surface 25 during operation, front and rearassemblies 54, 56 are pivotally coupled about jackshaft 86.

[0035] In an exemplary embodiment of the invention, cleaning dispenser22 includes a pump 30, shown fixed to the main assembly of machine10—see FIG. 1, for pumping cleaning liquid 13 through conduit 32 andnozzle 34 thereby delivering cleaning liquid 13 to brushes 62, 64.Appropriate fluid controls, such as switches, valves, etc. (not shown)are provided to control the application of cleaning fluid 13. Asdepicted in FIGS. 5 and 6, nozzle 34 spray is substantially directed tothe cleaning medium brushes 62, 64, and not surface 25. Alternativedispensing means may include drip bars or tubes (not shown) fortransferring cleaning liquid 13 to cleaning medium 40.

[0036] As indicated earlier, extraction system 24 is intended to removecleaning liquid 13 and any soil from the cleaning medium 40, for examplebrushes 62 and 64. In the embodiment of the invention illustrated in thedrawings, extraction system 24 includes a vacuum extractor 42 whichengages brushes 62, 64, a vacuum conduit 44, and a vacuum fan 46 toremove soiled solution from brushes 62, 64 and to transfer soiledsolution to recovery tank 14. As particularly illustrated in FIGS. 4 and5, extractor 42 includes a bifurcated end having a pair of elongatevacuum apertures 92, 94 in operational contact with associated cleaningmedium brushes 62, 64. Soiled solution and airflow through elongateapertures 92, 94 is joined at an upper portion of extractor 42 forfurther removal through hose 44 to recovery tank 14. Elongate apertures92, 94 are sized in relation to brushes 62, 64 to remove soiled solutionacross substantially the entire transverse length of the brushes. Analternative vacuum extractor may include two separate vacuum extractorheads each having separate conduits to the recovery tank. As depicted inFIG. 5, extractor 42 defines an interior region 98 in which nozzle 34 isprovided. A spray of cleaning solution 13 directed toward cleaningmedium 40, namely brushes 62 and 64, from nozzle 34 is intended to begenerally contained within interior region 98.

[0037]FIGS. 5-7 disclose an additional feature of the invention, that ofdrip guards 96. In the absence of drip guards 96, large droplets 97 ofcleaning solution formed on the walls 98 of the cleaning head 20 willtend to drop onto the carpet surface 25. This may result in a speckledor uneven appearance. Drip guards 96 serve to prevent droplets 97 fromreaching carpet surface 25 during the cleaning process. Drip guards 96extend substantially the entire length of cleaning brushes 64, 66 andare provided in contacting relation with cleaning brushes 64, 66. Dripguards 96 function to redirect cleaning solution thrown from brushes 64,66 back onto brush 64. As a result, large droplets 97 of cleaningsolution are prevented from being dropped onto the carpet surface 25.Drip guards 96 are illustrated as a generally planar form. Alternativeembodiments of drip guards 96 may include curved or other complex forms.Drip guards 96 may be formed as an integral portion of cleaning head 20or may be a separate attachment secured within cleaning head 20. In oneembodiment, drip guards 96 are formed from 0.060 inch thick steel. Inother embodiments, drip guards 96 may be formed from one or moredifferent materials and may have thicknesses which are different than0.060 inch think.

[0038] In operation, machine 10 is operator-propelled across a surface.In accordance with the present invention, machine 10 may bebi-directionaly operated—i.e., machine 10 may be propelled forwardly orrearwardly during operation. To initiate a cleaning operation,appropriate controls, such as switches (not shown), are used to activatevacuum motor 46, cleaning medium drive 60 and cleaning liquid pump 30.Upon activation, brushes 62, 64 of cleaning medium 40 are revolved viadrive assembly 60 and cleaning liquid 13 is dispensed through spraynozzle 34 to cleaning medium brushes 62, 64.

[0039] Wetted portions of brushes 62, 64 may be defined as those brushportions which receive cleaning liquid from the spray nozzle 34.Regarding brush 62, which rotates in a referenced clockwise manner, thewetted portion is generally that portion of brush 62 betweenapproximately 9 o'clock and 12 o'clock. Regarding brush 64, whichrotates in a referenced counterclockwise manner, the wetted portion isgenerally that portion of brush 64 between approximately 3 o'clock and12 o'clock. Referring to FIG. 6, wetted portions of brushes 62, 64 aredesignated as numerals 100, 102. The relative dampness or wetness ofwetted portions 100, 102 is of course dependent upon the quality of thespray exiting nozzle 34 and the rate of rotation of cylindrical brushed62 and 64. For example, increased wetness of brushes 62 and 64 may beachieved by a slower rate of rotation and/or increased spray throughnozzle 34.

[0040] Prior to wetted brush portions 100, 102 being rotated intocontact with carpet surface 25, the relative dampness is reduced byoperation of vacuum extractor 42. Vacuum extractor 42 engages each brush62, 64 to remove some of the just deposited cleaning liquid 13 and soilpreviously transferred from the carpet surface. Each brush 62, 64 of thecleaning medium 40 is engaged by respective vacuum apertures 92, 94 ofvacuum extractor 42 to reduce the local wetness of brushes 62, 64. As aresult, rotating brushes 62, 64 have a wetted portion 100, 102 asdefined above, and a reduced wetness portion 104, 106 which engages thecarpet surface and transfers soil from the carpet to brushes 62, 64.

[0041] As brushes 62, 64 are revolved, reduced wetness brush portions104, 106 engage the carpet fibers and cause soil to be transferred fromthe carpet fibers to brushes 62, 64. As brushes 62, 64 are furtherrotated, the reduced wetness portions 104, 106 (having received soilfrom the carpet) are sprayed with cleaning liquid through nozzle 34 andsubsequently vacuum extracted through extractor 42 to convey soiledcleaning liquid from brushes 62, 64 into soiled solution recovery tank14.

[0042] The cleaning process, in accordance with the present invention,thus includes the steps of wetting a portion of cleaning medium 40 withcleaning liquid 13, reducing the relative wetness of the wetted portionof the cleaning medium by extraction, and then wiping the surfaceintended to be cleaned with the cleaning medium so as to transfer soilfrom the surface intended to be cleaned to the cleaning medium 40. Soilupon the cleaning medium 40 is subsequently removed as the revolvingcleaning medium is rewetted and extracted. In turn, the aforesaidcleaning process repeats as a cycle with cleaning medium 40 revolving,cleaning liquid 13 being conveyed to cleaning medium 40, extractor 42reducing the relative wetness of a portion of the cleaning medium 40(and removing soiled solution therefrom), and cleaning medium 40 wipingthe carpet to transfer soil from the carpet to the cleaning medium 40.

[0043] Additional aspects of the present invention will be addressed. Itis envisioned that the cleaning process according to the presentinvention may be performed on a variety of different machines, rangingfrom small manually operated devices, to large self-propelled vehicles.The illustrated device is a self-contained portable cleaning machine,more particularly an operator propelled unit with solution, pump, brush,and vacuum recovery tank. In alternative embodiments, machine 11 mayinclude a vehicle, such as a ride-on or towed-behind vehicle, or be ahand held machine performing a cleaning operation as described herein.Machine 10 may be powered through an on-board power source, such asbatteries or an IC engine.

[0044] In alternative embodiments, cleaning head 20 may be provided asan accessory or optional item for use with other cleaning machines. Inother embodiments, cleaning head 20 may be utilized upon larger,operator driven machines.

[0045] Embodiments of the present invention may be utilized for cleaninga variety of floor surfaces, including but not limited to carpets, rugs,tile, vinyl, terrazzo, wood floors, and concrete surfaces. Additionalsurfaces which may be cleaning through a process as described hereininclude walls, stairways, upholstered furniture or fabric, such ascurtains and the like. In a particularly preferred embodiment and asdescribed herein with reference to machine 10 operation, the presentinvention is utilized for cleaning floor coverings.

[0046] Surface cleaning medium 40 may be one or more elongatedcylindrical elements, as depicted in the Figures, wherein each elongatedcylindrical element rotates about a generally horizontal axis ofrotation generally in parallel with the surface intended to be cleaned.The axis of rotation in a particularly preferred embodiment beingaligned generally transverse to the direction of intended machine 10operation. Alternatively, cleaning medium 40 may be one or moredisk-shaped elements which rotate about one or more generally verticalaxes of rotation generally transverse to the surface intended to becleaned.

[0047] Yet another embodiment of cleaning medium 40 may include a belt,with an outward belt surface being a cleaning medium, trained betweentwo or more rollers, the belt moving as the rollers rotate. With thisbelt-type cleaning medium, it should be appreciated that the belt isintended to revolve so that the outward belt surface having the cleaningmedium thereon sequentially passes a wetting operation, followed by anextraction process, followed by a soil transfer process—i.e., wiping theintended surface to be cleaned with cleaning medium surface of the belt.Additional embodiments of cleaning mediums are of course possible as maybe appreciated by those skilled in the relevant arts.

[0048] In another embodiment cleaning medium 40 may be a cylindricalshaped element having a combination of foam and bristle surfaces. (notshown) In alternative embodiments, cleaning medium 40 may comprise arevolving belt as aforesaid. Cleaning medium 40 may include a variety ofdifferent materials including fabrics, synthetic scouring pads and foamelements and the like which serve the intended function of transferringsoil from a surface being wiped onto the cleaning medium.

[0049] Extractor 42 may be provided by a wide array of structures andtechniques as may be appreciated by those skilled in the relevant artsincluding, including but not limited to non-vacuum techniques such aspressing or squeezing, all of which are intended to be within the truespirit and scope of the present invention.

[0050] Further, although cleaning solution dispenser 22 is illustratedas being operated by a pump on the main assembly of machine 10, otherarrangements are of course possible so as to achieve the intendedfunction. As used herein, and the appended claims, the cleaning liquidmay comprise any cleaning solution which assists the transfer of thesoil on the surface intended to be cleaned unto the cleaning medium. Forexample, cleaning liquid 13 could also be in the form of a foam, vapor,liquid with suspended solids, a granular cleaning material, plain water,and the like. Of course, liquid dispenser 22 would be of different formthan that as illustrated in order to accommodate the selected cleaningliquid or material. Therefore, as used herein and the appended claims,wetting of the cleaning medium encompasses, but not limited to,depositing, applying, or conveying such material onto the cleaningmedium 40.

[0051] In alternative embodiments of the present invention, cleaninghead 20 may be coupled to machine 10 via a plurality of pivot points, afour bar linkage, or alternative structures which facilitate headmovement and cleaning medium engagement across both even and unevenfloor surfaces.

[0052] Other modifications to the described embodiment may also bepracticable. One or more cleaning liquid dispensing devices may beutilized in alternative embodiments of the invention. Additionally, thevacuum extractor may be alternatively configured and include a differentextractor structure. For example, a plurality of vacuum extractinglocations may be practicable, i.e., a first vacuum extraction locationfor reducing the relative dampness of the rotating cleaning medium priorto contact with the floor surface, and a second vacuum extractionlocation for removing soiled solution from the cleaning medium. In yetanother example, a rotating belt machine may include a first cleaningliquid dispensing device, a first extraction device for reducing thedampness of the belt prior to contact with carpet, a second cleaningliquid dispensing device, and a second extraction device for removingsoiled solution from the belt. As various changes could be made in theabove methods and devices without departing from the scope of theinvention, it is intended that all matter contained in the abovedescription or shown in the accompanying drawings shall be interpretedas illustrative and not in a limiting sense. Definitions are providedherein with reference to terms used in the specification and appendedclaims:

[0053] “Revolving”: 1. Tending to revolve or happen repeatedly. 2.Available at regular intervals. As used herein, the term broadlydescribes a cyclical movement of the cleaning medium relative to thesurface. A cylindrical shaped “revolving” cleaning medium may be rotatedabout an axis of rotation. A belt shaped “revolving” cleaning medium maybe supported for movement about a pair or more rotating elements, e.g.,rollers, etc. More complex motions or movements of the cleaning mediumrelative to the floor are also intended to be included within the broaddefinition of the term revolving, including but not limited tooscillatory and/or motions.

[0054] “Extracting”: 1. Drawing or pulling out, using force or effort.2. To remove or obtain from a substrate by mechanical action, as bymechanical pressure or vacuum. As used herein, the term broadlydescribes the step of removing cleaning liquid and/or soil from thecleaning medium. The step of extracting may be achieved through amechanical shearing type operation, or a vacuum removal operation, orboth.

[0055] “Wiping”: 1. Engaging, contacting. As used herein, the termbroadly describes physical engagement between the cleaning medium andthe surface being cleaned. Each of a rotating elongated cylindricalbrush, disk brush or pad when engaging a surface to be cleaned isconsidered to be in “wiping” contact with the surface. Wiping does notnecessarily imply or suggest removing liquid from a surface. In a carpetcleaning device of the present invention, a cleaning medium being wipedagainst the carpet surface would transfer some amount of cleaning liquidto the carpet surface.

We claim:
 1. A method of mechanically removing soil from a surfaceintended to be cleaned, said method being performed by a surfacemaintenance machine and comprising the steps of repeatedly: wetting aportion of a revolving cleaning medium with a cleaning liquid;extracting some soil and some of the cleaning liquid from the previouslywetted portion of the cleaning medium; and wiping the surface intendedto be cleaned with the portion of the revolving cleaning medium so as totransfer soil from the surface intended to be cleaned to the cleaningmedium.
 2. The method of claim 1 further comprising the step ofextracting soil and cleaning liquid on the portion of the cleaningmedium previous wiped against the surface intended to be clean and priorto again wetting the same portion.
 3. An automated method of removingsoil from a surface intended to be cleaned by a movable machine having arevolving cleaning medium comprising the steps of repeatedly: wetting aportion of the revolving cleaning medium with a cleaning liquid;extracting some soil and some of the cleaning solution from saidpreviously wetted portion of the revolving cleaning medium; and wipingthe surface with said portion of the revolving cleaning mediumpreviously extracted so as to transfer soil from the surface intended tobe cleaned to the revolving cleaning medium.
 4. The method of claim 3further comprising the step of extracting soil and cleaning solutionfrom the portion of the cleaning medium previously wiped against thesurface intended to be clean prior to again wetting the same portion. 5.A method of removing soil from a surface intended to be cleaned using amovable machine, said method comprising the steps of: moving the movablemachine across the surface while performing the steps of: wetting aportion of a revolving cleaning medium with a cleaning liquid;extracting soil and cleaning liquid from said portion of the revolvingcleaning medium; and wiping the surface with said portion of therevolving cleaning medium so as to transfer soil from the surfaceintended to be cleaned to the cleaning medium
 6. The method of claim 5wherein the step of wetting the portion of the revolving cleaning mediumincludes spraying cleaning liquid onto the cleaning medium.
 7. Themethod of claim 5 wherein the step of extracting soil and cleaningliquid from the portion of the cleaning medium is achieved through avacuum extractor.
 8. The method of claim 5 wherein the cleaning mediumincludes at least one elongated generally cylindrical shaped elementrotating generally about an axis of rotation.
 9. The method of claim 8wherein the cleaning medium includes a pair of elongated generallycylindrical shaped elements which are counter-rotated relative to eachother, and wherein said axis of rotation is generally parallel with thesurface intended to be cleaned.
 10. The method of claim 9 wherein thestep of extracting is achieved through a pair of vacuum apertures, eachof said pair of vacuum apertures being associated with a different oneof the counter-rotated elongated generally cylindrical shaped elements.11. The method of claim 8 wherein the axis of rotation is aligned in adirection generally transverse to an operational direction of devicemovement across the surface.
 12. The method of claim 5 wherein thesurface is a carpet surface, and wherein the step of wiping the surfacetransfers soil from fibers of the carpet surface to the cleaning medium.13. The method of claim 5 wherein the surface is a fabric surface, andwherein the step of wiping the surface transfers soil from fibers of thefabric surface to the cleaning medium.
 14. The method of claim 5 whereinthe movable machine includes at least one drip guard in contact with atleast a portion of the cleaning medium for redirecting cleaning solutionwithin a cleaning head toward the cleaning medium.
 15. A method ofcleaning a carpeted surface, said method being performed by a surfacemaintenance machine and comprising the steps of repeatedly: spraying aportion of a revolving cleaning medium with a cleaning liquid; removingsome soil and some of the cleaning liquid from the previously wettedportion of the cleaning medium using a vacuum device; and wiping thecarpeted surface with the portion of the revolving cleaning medium so asto transfer soil from the carpeted surface to the cleaning medium. 16.The method of claim 15 wherein the step of spraying involves pumping acleaning liquid from a reservoir carried by the surface maintenancemachine.
 17. The method of claim 15 wherein the step of removinginvolves applying a vacuum to the previously wetted portion of thecleaning medium so as to convey soil and cleaning liquid to a receptacleof soiled solution carried by the surface maintenance machine.
 18. Themethod of claim 15 wherein the step of wiping involves rotating acylindrical cleaning medium in contact with the carpeted surface. 19.The method of claim 18 wherein the cylindrical cleaning medium isrotated about an axis which is generally perpendicular to a direction ofmachine use.
 20. The method of claim 15 wherein the surface maintenancemachine either a self-propelled machine or a non-propelled machine. 21.The method of claim 15 wherein the movable machine includes at least onedrip guard in contact with at least a portion of the cleaning medium forredirecting cleaning solution within a cleaning head toward the cleaningmedium.
 22. A method of cleaning a carpeted surface, said method beingperformed by a surface maintenance machine and comprising the steps ofrepeatedly: spraying a portion of a revolving cleaning medium with acleaning liquid; removing some soil and some of the cleaning liquid fromthe previously wetted portion of the cleaning medium using a vacuumdevice; wiping the carpeted surface with the portion of the revolvingcleaning medium so as to transfer soil from the carpeted surface to thecleaning medium, said step of wiping causing an amount of cleaningliquid to be thrown from the cleaning medium into contact with interiorsurfaces of a cleaning head; and redirecting the amount of cleaningliquid thrown from the cleaning medium back toward the cleaning mediumso as to minimize the dropping of large droplets of cleaning solutiononto the carpeted surface.